Voltage stability analysis of wind farms integration connected to distribution network

With the increasing scale of wind power generation, the impact on the power flow direction, voltage stability and relay protection coordination has been widely concerned. By utilizing the measured electric data such as bus voltage phasors, line parameters, and according to the voltage quadratic equations of power flow, a new voltage stability index is proposed. Gust causes wind power to produce peak output power and leads to reduced voltage regulation capability of the feeder, which may lead to voltage collapse without sufficient reactive power support. The accurate voltage stability index (VSI) is the voltage stability margin that needs real-time quantification. In this paper, a voltage stability index suitable for distribution systems is proposed, which is only required to be measured at the root of feeders. The proposed VSI has been simulated in the distribution network with different types of fans, and the results show that the proposed VSI has the ability to quantify the node voltage stability margin in real time and effectively.